Create blog post on Bootstrap migration and Docsy upgrade for projects

- This is part two of #1535, which was published and cross-posted to (respectively)
  - https://www.cncf.io/blog/2023/06/05/migrating-docsy-to-bootstrap-5/
  - https://www.docsy.dev/blog/2023/bootstrap-5-migration/
- Will be using OTel and the docsy-example as case studies, in particular